From nobody Mon Jun 8 20:53:43 2026 Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id C682F1DED49; Tue, 26 May 2026 14:22:25 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=193.142.43.55 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779805347; cv=none; b=itFPjSpmT04s7nEwCGsZJglpTZxG0aNBJGgzL9Hmm3ekUqB8ttPyp7t6fA5yf1fu5iRFDl+umXb3PJ7kTGokEDh4Vd1HmkgkBdi90TQ15IYal4OQKrl4mc8m8NxdY5Hy2UDi7xBcq4ManuLx6SgxmlZOxHFaZ99QwBnzsVpDcak= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779805347; c=relaxed/simple; bh=yKjjA2zbp8OoqyI+2QpB6XevUvYWQmQvJeblsNDnlvU=; h=Date:From:To:Subject:Cc:In-Reply-To:References:MIME-Version: Message-ID:Content-Type; b=AGguJcrjk3eN0qAsN2lVmEH++q4EPTXPvQj2tvzlMaY17NugeLikleVhy+hpOh6PBg6sDaCI9tYAdIB1HgSC8Kp8ZrI7Gz5GSMXNUplUnOzvp8GsswFnv2r3QS/DStEYN+j3Ah1V3EjJoz3bsnmM7dFaOuIk9/48GFNazLIxduY= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de; spf=pass smtp.mailfrom=linutronix.de; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=gsa8qp93; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=eDdR/97g; arc=none smtp.client-ip=193.142.43.55 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linutronix.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="gsa8qp93"; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="eDdR/97g" Date: Tue, 26 May 2026 14:22:22 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1779805343; h=from:from:sender:sender:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=e31a7JFfsCO6iFfoXB/joDJoVFhtSwcZCzClTFZbHjo=; b=gsa8qp935lbMZloqla9in56jvxPblqTAnhisnym0I3ikCGnQZbd6FOwc2N4ZriuMkVszhQ 3n2/zDNGggNuS/RwmQSLusBHw2paignRwpquYPe5WsvHfA+ETj2sB4j3Aa83Ki9RL3TQ0/ g9Zcyh5VJVD8cCNOV0D9k6BKXEsroFAP6bvoNzBptIhHgy1OrnIAoGkUd5O0Q+pIMZuwSJ EGOr3KgHDe8u8B5bg3YorCaEG10Qf/aOsVXVj4Fb2Ew/S6zkvZyCgLmdZu8OoMZMQn26ie 6B6gUwqtfz/hXE2HhXdMDbiJKqw02K0IehD/5+3WahUWxvqJsPnkb3GJZBkcmQ== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1779805343; h=from:from:sender:sender:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=e31a7JFfsCO6iFfoXB/joDJoVFhtSwcZCzClTFZbHjo=; b=eDdR/97gEcqTiOpQRD7uTOKiMJhEFO6/2X2V4p2oSof/C97SMwn54bB8ncgC3bSUVHTpdl PBHeHoZ3gKbkqXDQ== From: "tip-bot2 for Thomas Gleixner" Sender: tip-bot2@linutronix.de Reply-to: linux-kernel@vger.kernel.org To: linux-tip-commits@vger.kernel.org Subject: [tip: irq/core] genirq: Add rcuref count to struct irq_desc Cc: Thomas Gleixner , Michael Kelley , Dmitry Ilvokhin , x86@kernel.org, linux-kernel@vger.kernel.org, maz@kernel.org In-Reply-To: <20260517194931.917415190@kernel.org> References: <20260517194931.917415190@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-ID: <177980534244.1039918.8146401454125716897.tip-bot2@tip-bot2> Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails Precedence: bulk Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable The following commit has been merged into the irq/core branch of tip: Commit-ID: 1d9c4745bfb6773712751f5068c23ebad9cd30a0 Gitweb: https://git.kernel.org/tip/1d9c4745bfb6773712751f5068c23ebad= 9cd30a0 Author: Thomas Gleixner AuthorDate: Sun, 17 May 2026 22:02:34 +02:00 Committer: Thomas Gleixner CommitterDate: Tue, 26 May 2026 16:21:14 +02:00 genirq: Add rcuref count to struct irq_desc Prepare for a smarter iterator for /proc/interrupts so that the next interrupt descriptor can be cached after lookup. Signed-off-by: Thomas Gleixner Tested-by: Michael Kelley Reviewed-by: Dmitry Ilvokhin Link: https://patch.msgid.link/20260517194931.917415190@kernel.org --- include/linux/irqdesc.h | 2 ++ kernel/irq/internals.h | 17 ++++++++++++++++- kernel/irq/irqdesc.c | 21 +++++++++++++-------- 3 files changed, 31 insertions(+), 9 deletions(-) diff --git a/include/linux/irqdesc.h b/include/linux/irqdesc.h index 1058786..8080db1 100644 --- a/include/linux/irqdesc.h +++ b/include/linux/irqdesc.h @@ -70,6 +70,7 @@ struct irq_redirect { * IRQF_NO_SUSPEND set * @force_resume_depth: number of irqactions on a irq descriptor with * IRQF_FORCE_RESUME set + * @refcnt: Reference count mainly for /proc/interrupts * @rcu: rcu head for delayed free * @kobj: kobject used to represent this struct in sysfs * @request_mutex: mutex to protect request/free before locking desc->lock @@ -119,6 +120,7 @@ struct irq_desc { struct dentry *debugfs_file; const char *dev_name; #endif + rcuref_t refcnt; #ifdef CONFIG_SPARSE_IRQ struct rcu_head rcu; struct kobject kobj; diff --git a/kernel/irq/internals.h b/kernel/irq/internals.h index be702dd..bacbf40 100644 --- a/kernel/irq/internals.h +++ b/kernel/irq/internals.h @@ -9,6 +9,7 @@ #include #include #include +#include #include =20 #ifdef CONFIG_SPARSE_IRQ @@ -101,9 +102,23 @@ extern void unmask_irq(struct irq_desc *desc); extern void unmask_threaded_irq(struct irq_desc *desc); =20 #ifdef CONFIG_SPARSE_IRQ -static inline void irq_mark_irq(unsigned int irq) { } +static __always_inline void irq_mark_irq(unsigned int irq) { } +void irq_desc_free_rcu(struct irq_desc *desc); + +static __always_inline bool irq_desc_get_ref(struct irq_desc *desc) +{ + return rcuref_get(&desc->refcnt); +} + +static __always_inline void irq_desc_put_ref(struct irq_desc *desc) +{ + if (rcuref_put(&desc->refcnt)) + irq_desc_free_rcu(desc); +} #else extern void irq_mark_irq(unsigned int irq); +static __always_inline bool irq_desc_get_ref(struct irq_desc *desc) { retu= rn true; } +static __always_inline void irq_desc_put_ref(struct irq_desc *desc) { } #endif =20 irqreturn_t __handle_irq_event_percpu(struct irq_desc *desc); diff --git a/kernel/irq/irqdesc.c b/kernel/irq/irqdesc.c index 90595ee..23f2176 100644 --- a/kernel/irq/irqdesc.c +++ b/kernel/irq/irqdesc.c @@ -137,6 +137,7 @@ static void desc_set_defaults(unsigned int irq, struct = irq_desc *desc, int node, desc->tot_count =3D 0; desc->name =3D NULL; desc->owner =3D owner; + rcuref_init(&desc->refcnt, 1); desc_smp_init(desc, node, affinity); } =20 @@ -465,6 +466,17 @@ static void delayed_free_desc(struct rcu_head *rhp) kobject_put(&desc->kobj); } =20 +void irq_desc_free_rcu(struct irq_desc *desc) +{ + /* + * We free the descriptor, masks and stat fields via RCU. That + * allows demultiplex interrupts to do rcu based management of + * the child interrupts. + * This also allows us to use rcu in kstat_irqs_usr(). + */ + call_rcu(&desc->rcu, delayed_free_desc); +} + static void free_desc(unsigned int irq) { struct irq_desc *desc =3D irq_to_desc(irq); @@ -483,14 +495,7 @@ static void free_desc(unsigned int irq) */ irq_sysfs_del(desc); delete_irq_desc(irq); - - /* - * We free the descriptor, masks and stat fields via RCU. That - * allows demultiplex interrupts to do rcu based management of - * the child interrupts. - * This also allows us to use rcu in kstat_irqs_usr(). - */ - call_rcu(&desc->rcu, delayed_free_desc); + irq_desc_put_ref(desc); } =20 static int alloc_descs(unsigned int start, unsigned int cnt, int node,